In contrast to conventional electrical ballasts, supply units of LED units work with different loads. The term LED (light emitting device) hereinafter also encompasses so-called OLEDs (organic light emitting device). Generally, such supply units supply only one output voltage for supplying power to a connected LED unit. If a plurality of LED units or different LED units are intended to be supplied with power by the supply unit, then the supply unit has to be designed for supplying power to a plurality of LED units or different LED units and acquire the information necessary for the power supply by way of rated parameters of the LED units to be supplied.